Compounds having the following formula are known from Belgian Pat. Nos. 698 384 and 764 362: ##STR2##
In this formula, one or more of the radicals R.sub.1 to R.sub.4 represent amino groups which may be acylated or alkylated by low molecular weight radicals, and, where the radicals R.sub.1 to R.sub.4 do not represent amino groups, then they represent hydrogen or halogen atoms, low molecular weight alkyl-, trifluoromethyl-, cyano-, thiocyano-, mercapto-, low molecular weight alkylthio-, acylthio-, hydroxy-, methylenedioxy-, low molecular weight alkoxy-, acyloxy-, nitro-, carboxy-, carbalkoxy- or carbamoyl groups, R.sub.5 represents a hydrogen atom or an acyl radical, R.sub.6 represents a hydrogen atom, a low molecular alkyl- or an aralkyl group and X represents a nitrogen weight atom or the CH group and wherein the acyl radicals are derived from carbonic acid, carbonic acid semi-morpholid, from carbonic acid monoesters, preferably from, substituted benzoic acids and pyridine carboxylic acids or from saturated or unsaturated, low molecular weight aliphatic mono- or dicarboxylic acids optionally substituted by a morpholino radical.
The compounds possess anti-inflammatory and analgesic action, the analgesic effect being specifically an analgesic action on the central nervous system, that is an action within the nerve cells of the spinal cord and/or the nerve cells of the brain.